JPS6030943A - Control device of hot-water storage type electric hot-water heater - Google Patents

Abstract

PURPOSE:To contrive to utilize the performance of the titled heater according to the actual requirement of user by a method wherein the necessary amount of heat required to be stored in a hot-water storage tank is calculated based on the actual amount of the hot-water consumed by the user and the predetermined necessary amount for the next day inputted by an inputting device. CONSTITUTION:The amount of heat KG for the required amount of hot-water of the day is obtained with a necessary amount of heat calculating device 16, the data is inputted into a memory device 12, simultaneously, the predetermined necessary amount of hot-water for the next day is selected from among the previously prepared control pattern, then inputted by an inputting device 18. Therefore, a time switch 8 is made ON at midnight, then a control is started. At first, the maximum data KGmax is called from among the up-to-date data by the memory device 12, a necessary amount of heat KS is preset by a necessary amount of heat presetting device 13. A heating up temperature To is preset based on a water supply temperature Ti in a hot-water storage tank 1 and the storage tank capacity Vt. Thus, a central control device transmits the energizing start signal to each heater for levelling of load through the entire time zone of midnight electric power supply service time zone.

Description

[Detailed Description of the Invention] The present invention relates to a control device for a hot water storage type electric water heater that utilizes late-night electricity, and is based on the actual amount of hot water used by the user and the expected amount of water used the next day inputted from an input device. By calculating the required amount of heat that should be stored in the hot water storage tank, the capacity of the conventional hot water storage type electric water heater can be used according to the user's actual situation.
The purpose is to level out and control multiple hot water storage type electric water heaters using a central control unit.

FIG. 1 is a block diagram of a general hot water storage type electric water heater, and FIG. 2 is a main electrical circuit diagram of a conventional hot water storage type electric water heater.

In these figures, 1 is a hot water storage tank, 2 is a water supply pipe, and 3 is a hot water storage tank.
is a hot water pipe, 4 is a hot water tap, 5 is a heating element, 6 is an automatic temperature controller, 7 is a power supply, and 8 is a time switch for late-night power, which is generally turned on from 11:00 p.m. to 7:00 the next morning. No. 8
It's time.

Next, the operation of the conventional example having the above configuration will be explained. When the time to start supplying late-night power comes, the contact of the time switch 8 is closed and the supply of electricity to the heating element 5 is started. When the temperature of the hot water in the hot water storage tank 1 reaches 85° C., the contacts of the automatic temperature regulator 6 are opened and the power supply to the heating element 5 is stopped. After that, the temperature of the water is 85"0C by opening and closing the automatic temperature controller 6.
In this way, the entire stored hot water is heated to 85°C every morning.

In this manner, in order to increase hot water storage efficiency, the hot water storage type electric water heater has a structure in which the boiling temperature is set as high as possible, and heating stops when the set temperature is reached. However, users do not use high-temperature hot water as it is, but mix it with water and use it as a mixed hot water at around 40 to 45°C. The formula for calculating the amount of mixed hot water obtained is as follows.

Now, the hot water storage tank capacity is vt (M), the boiling temperature in hot water storage tank 1 is To ('C), the temperature of the mixed hot water to be obtained is Tm ('O), and the temperature of the water to be mixed (water supply temperature). If Ti('(rit), then the amount of mixed hot water Vm(
sentence) can be expressed as .

In this formula, the water supply temperature Ti varies greatly depending on the season. In Tokyo, the temperature ranges from around 5°C in winter to around 27°C in summer. Therefore, the amount of hot water that can be obtained as mixed hot water at an appropriate temperature is small in the winter and large in the summer. That is, when the boiling temperature To is 85°C, the amount of mixed hot water Vm obtained when the water supply temperature Ti is 5°C is 1.6 times that obtained when the water supply temperature Ti is 27°C.

On the other hand, the amount of hot water used is approximately constant throughout the year, or in fact, the actual amount used generally decreases in the summer because hot water is used at a lower temperature, and the amount of hot water remaining in the summer is larger than in the winter. . Furthermore, some users use only 1/2 or 2/3 of the rated amount due to a decrease in the number of family members, leaving a large amount of hot water every day.

In this way, if the water supply temperature is high or there is residual hot water, the hot water will boil quickly and the hot water will be left unused for a long time.

In this way, leaving unnecessarily high-temperature hot water unused for a long time has the disadvantage of increasing heat loss due to natural heat radiation from the hot water storage tank 1 and heat radiation from hot water stagnant in the pipes. was there. In addition, since each machine was heated up in a short period of time, there was a problem that the load was concentrated in the first half of the late night power-on time.

This invention attempts to eliminate these drawbacks.
The amount of hot water used, for example, the amount of hot water used in the past 10 days, is stored in the storage device as heat amount data, and this data is stored every day.
It is updated based on the amount of hot water used that day, that is, it has a learning function, and based on this data, the required amount of mixed hot water is controlled by controlling the required energization time to the heating element, thereby reducing the amount of remaining hot water. At the same time, the heat loss after boiling is eliminated as much as possible. This invention manages a plurality of hot water storage type electric water heaters with a central control device, and distributes the start time of energization so that the load is evenly distributed throughout the late night power supply period. be.

Figure 3 shows the configuration of a hot water storage type electric water heater which is the object of control of this invention.
Shows the same thing as the figure. 9 is a temperature detection means (hereinafter referred to as a temperature sensor) such as a thermistor, which continuously detects the temperature of water supplied from the water supply pipe 2 into the hot water storage tank 1, and also detects the temperature of boiling water. Yes, it is located at the bottom of the hot water storage tank 1. Note that this temperature sensor 9 may be provided separately to detect the temperature of water and the temperature of hot water, respectively. Reference numeral 10 denotes a switch for controlling the supply of electricity to the heating element 5, which is opened and closed by the operation of a control section, which will be described later. Reference numeral 11 denotes the above-mentioned control unit, which includes a storage device 12. Required heat amount setting device 1
3. Boiling temperature setting device 149 energization control device 15. and the amount of heat used @ calculation device 16. 17 is a water meter,
It is attached to the water supply pipe 2 and indirectly measures the flow rate of hot water flowing out from the hot water storage tank 1. For example, an encoder is attached to a metering propeller that rotates depending on the flow rate.
A device that generates the number of pulses depending on the flow rate is used. Note that the water meter 17 may be provided on the hot water supply pipe 3 side. Also, 1
8 is an input device.

The storage device 12 stores the amount of heat of the amount of hot water used calculated in the amount of heat used calculation cm16, and the actual results KG for several days thereof as data. This data is set to a fixed number of days, such as 10 days, so that the latest data is always saved.

The required heat amount setting device 13 calls the maximum value KGmax of the data stored therein (in the above example, for 10 days) from the storage device 12, for example, and sets it to a constant C based on the margin rate (for example, margin rate 10). %, it becomes 1.1) to calculate the required amount of heat Ks (k
cal ) is calculated as Ks = KGmaxX C .

The boiling temperature setting device 14 sets the required amount of heat Ks (k ca
l), hot water storage tank capacity vt(i), water supply temperature Ti
('0) to boiling temperature T. (°C) from the formula below.

The energization control device 15 turns on the switch 1o.

It is controlled to turn off, and is turned on by a command from a central control device, which will be described later, and turned off when the temperature sensor 9 detects the boiling temperature T.

The amount of heat used calculation device 16 calculates the required amount of heat KG for the previous day, where the amount of hot water used by the water meter 17 is V(1, the water supply temperature is Ti ('O), and the boiling temperature of the previous day is To ('c). Calculated as VX (To - Ti).

The input device 18 may say, for example, "take a bath."

Select the next day's hot water usage schedule from pre-prepared control patterns such as "No bathing" i? It is something.

FIG. 4 is a block diagram of the overall configuration showing one embodiment of the present invention. In this diagram, 100A, 100B,...
100N indicates the above-mentioned hot water storage type electric water heater according to the present invention, and inside the control unit 11, only the required heat amount setting device 13 and the energization control device 15 necessary for explanation are shown, and the others are omitted. Reference numeral 200 denotes a central control device that receives data on the required heat amount of each hot water storage type electric water heater 100A to 10ON from the setting device 13, and adjusts the amount of heat required for each of the hot water storage type electric water heaters 100A to 10ON so that the load is evenly distributed throughout the late night power supply period. Allocate the start time of energization. There are various methods of leveling, but the simplest way is to turn on each hot water storage type electric water heater one after another.

Just turn it off. In short, the central control device 200 issues a control command to each energization control device 15 so that the peak is leveled and the load approaches a uniform load.

Next, the operation of the above embodiment will be explained with reference to FIG. Note that (1) to (13) in FIG. 5 represent each step.

At the start 1), at the end of the day's use of hot water, that is, before midnight power is supplied to the electric water heater, the amount of heat KG for the amount of hot water used that day is determined by the amount of heat used calculation device 16 (2) , this data is input to the storage device 12, and the data previously stored in the storage device 12 is updated (3).

Therefore, at midnight, for example at 23:00, the time switch 8 is turned on (4). When control is started at the same time as this energization, first, the largest value KGmax among the latest data is called from the storage device 12 (5), and the required heat amount setting device 13 sets a constant C based on KGmax with a margin factor. The required amount of heat Ks is set by multiplying (6). Further, in the boiling temperature setting device 14, the temperature sensor 9 measures the water supply temperature Ti in the hot water storage tank 1 (7), and the boiling temperature T is set from the hot water storage tank capacity Vt (8).

In this way, when the boiling temperature set for each water heater is input to the central controller 200, the central controller 200
0 sends a signal to start energizing each machine based on the boiling temperature so that the load is evenly distributed throughout the late night power supply period. In this way, upon receiving a signal to start energization, each of them starts energizing the heating element 5 (8). Then, when the water temperature reaches the boiling temperature (lO), the power to the heating element 5 is turned off (11).

Then, at the end of the midnight power supply time, for example 7 o'clock, the time switch 8 is turned off (12) and the sequence is stopped (13).

In the above embodiment, the required heat amount setting device 13 calculates the required heat amount Ks by using the maximum K in the data in the storage device 12.
Although Gmax is used, an average over a fixed number of days or other data may also be used. In addition, the control unit 1
1, a microcomputer equipped with a central processing unit (CPU) can be used.

Further, in the above embodiment, each hot water storage type electric water heater is controlled to be energized in sequence, but the present invention is not limited to this, and multiple units may be energized at the same time. It is sufficient if the power consumption is leveled out.

As explained in detail above, this invention stores the latest data on the amount of heat for the amount of hot water used as past results in the storage device, and generates heat based on this data and data on the amount of water scheduled to be used for the next day from the input device. Since the amount of heat supplied to the body is determined, the amount of hot water that is provided to the user's body can be obtained every day according to the actual situation of the user.This, combined with the use of the input device, reduces the amount of remaining hot water, thus reducing heat loss after boiling. This reduces maintenance costs. Furthermore, the central control unit allocates the start times of energizing multiple hot water storage type electric water heaters so that the load is evenly distributed throughout the late night power supply period, which is expected to improve power transmission efficiency. has advantages.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a general hot water storage type electric water heater, Figure 2 is a main electrical circuit diagram of a conventional hot water storage type electric water heater, and Figure 3 is a diagram of the main electrical circuit diagram of a conventional hot water storage type electric water heater.
FIG. 4 is a block diagram showing the overall structure of an embodiment of the invention, and FIG. 5 is a control flowchart thereof. In the figure, 1 is a hot water storage tank, 2 is a water supply pipe, 3 is a hot water supply pipe, 4 is a hot water tap, 5 is a heating element, 7 is a power supply, 8 is a time switch,
9 is a temperature sensor, 10 is a switch, 11 is a control unit, 1
2 is a storage device, 13 is a required heat amount setting device, 14 is a boiling temperature setting device, 15 is an energization control device, 16 is a usage amount calculation device, 17 is a water meter, 18 is an input device, 100A~
10ON is a hot water storage type electric water heater, and 200 is a central control device. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Figure 4 Figure 5

Claims (1)

[Claims] A heating element that heats water in a hot water storage tank using late-night electricity, a temperature detection means that detects the temperature of water supplied to the hot water storage tank and the boiling temperature, and an input device that inputs the amount of water scheduled to be used for the next day. a storage device that stores the actual amount of hot water used as heat amount data; a required heat amount setting device that sets the required amount of heat to be stored in the hot water storage tank based on the data; and the water supply temperature, the required amount of heat, and the hot water storage tank capacity. a boiling temperature setting device for setting a boiling temperature from the heating element, and a boiling temperature detected by the temperature detecting means by turning on electricity to the heating element and reaching the boiling temperature set by the boiling temperature setting device. A hot water storage type electric hot water system comprising: an energization control device that occasionally stops energizing the heating element; and a used heat amount calculation device that calculates the amount of heat used and inputs the value into the storage device to update the data. A central control device is installed that distributes the start of electricity so that multiple units of water heaters are grouped together and the power supplied to each storage type electric water heater is distributed evenly over the entire late night power supply period. A control device for a hot water storage type electric water heater.